From f4a513a98e6341b2d4796752644a27c722612847 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Thu, 29 Oct 2015 18:14:50 +0000 Subject: compiler, reflect, runtime: remove zero field from type descriptor Type descriptors picked up a zero field because the gc map implementation used it. However, it's since been dropped by the gc library. It was never used by gccgo. Drop it now in preparation for upgrading to the Go 1.5 library. Reviewed-on: https://go-review.googlesource.com/16486 From-SVN: r229546 --- libgo/go/reflect/type.go | 6 ------ libgo/runtime/go-type.h | 5 ----- libgo/runtime/go-unsafe-pointer.c | 11 ++--------- libgo/runtime/proc.c | 4 +--- 4 files changed, 3 insertions(+), 23 deletions(-) (limited to 'libgo') diff --git a/libgo/go/reflect/type.go b/libgo/go/reflect/type.go index 61b1955..5cdfba5 100644 --- a/libgo/go/reflect/type.go +++ b/libgo/go/reflect/type.go @@ -262,7 +262,6 @@ type rtype struct { string *string // string form; unnecessary but undeniably useful *uncommonType // (relatively) uncommon fields ptrToThis *rtype // type for pointer to this type, if used in binary or has methods - zero unsafe.Pointer // pointer to zero value } // Method on non-interface type @@ -1129,7 +1128,6 @@ func (t *rtype) ptrTo() *rtype { p.uncommonType = nil p.ptrToThis = nil - p.zero = unsafe.Pointer(&make([]byte, p.size)[0]) p.elem = t if t.kind&kindNoPointers != 0 { @@ -1505,7 +1503,6 @@ func ChanOf(dir ChanDir, t Type) Type { ch.elem = typ ch.uncommonType = nil ch.ptrToThis = nil - ch.zero = unsafe.Pointer(&make([]byte, ch.size)[0]) ch.gc = unsafe.Pointer(&chanGC{ width: ch.size, @@ -1561,7 +1558,6 @@ func MapOf(key, elem Type) Type { mt.elem = etyp mt.uncommonType = nil mt.ptrToThis = nil - mt.zero = unsafe.Pointer(&make([]byte, mt.size)[0]) // mt.gc = unsafe.Pointer(&ptrGC{ // width: unsafe.Sizeof(uintptr(0)), // op: _GC_PTR, @@ -1848,7 +1844,6 @@ func SliceOf(t Type) Type { slice.elem = typ slice.uncommonType = nil slice.ptrToThis = nil - slice.zero = unsafe.Pointer(&make([]byte, slice.size)[0]) if typ.size == 0 { slice.gc = unsafe.Pointer(&sliceEmptyGCProg) @@ -1920,7 +1915,6 @@ func arrayOf(count int, elem Type) Type { // TODO: array.uncommonType = nil array.ptrToThis = nil - array.zero = unsafe.Pointer(&make([]byte, array.size)[0]) array.len = uintptr(count) array.slice = slice.(*rtype) diff --git a/libgo/runtime/go-type.h b/libgo/runtime/go-type.h index 72c9f56..eb063ec 100644 --- a/libgo/runtime/go-type.h +++ b/libgo/runtime/go-type.h @@ -108,11 +108,6 @@ struct __go_type_descriptor /* The descriptor for the type which is a pointer to this type. This may be NULL. */ const struct __go_type_descriptor *__pointer_to_this; - - /* A pointer to a zero value for this type. All types will point to - the same zero value, go$zerovalue, which is a common variable so - that it will be large enough. */ - void *__zero; }; /* The information we store for each method of a type. */ diff --git a/libgo/runtime/go-unsafe-pointer.c b/libgo/runtime/go-unsafe-pointer.c index a59ae85..ce82fcd 100644 --- a/libgo/runtime/go-unsafe-pointer.c +++ b/libgo/runtime/go-unsafe-pointer.c @@ -10,9 +10,6 @@ #include "go-type.h" #include "mgc0.h" -/* A pointer with a zero value. */ -static void *zero_pointer; - /* This file provides the type descriptor for the unsafe.Pointer type. The unsafe package is defined by the compiler itself, which means that there is no package to compile to define the type @@ -64,9 +61,7 @@ const struct __go_type_descriptor unsafe_Pointer = /* __uncommon */ NULL, /* __pointer_to_this */ - NULL, - /* __zero */ - &zero_pointer + NULL }; /* We also need the type descriptor for the pointer to unsafe.Pointer, @@ -109,9 +104,7 @@ const struct __go_ptr_type pointer_unsafe_Pointer = /* __uncommon */ NULL, /* __pointer_to_this */ - NULL, - /* __zero */ - &zero_pointer + NULL }, /* __element_type */ &unsafe_Pointer diff --git a/libgo/runtime/proc.c b/libgo/runtime/proc.c index db8b94f..8f82f5b 100644 --- a/libgo/runtime/proc.c +++ b/libgo/runtime/proc.c @@ -538,9 +538,7 @@ static struct __go_channel_type chan_bool_type_descriptor = /* __uncommon */ NULL, /* __pointer_to_this */ - NULL, - /* __zero */ - NULL /* This value doesn't matter */ + NULL }, /* __element_type */ &bool_type_descriptor, -- cgit v1.1